一个新的增算子不动点定理

本文在新的条件下，证明了增算子不动点的存在性．     

Asymptotic distributions of functions of a sample covariance matrix under the elliptical distribution

This paper is concerned with asymptotic distributions of functions of a sample covariance matrix under the elliptical model. Simple but useful formulae for calculating asymptotic variances and covariances of the functions are derived. Also, an asymptotic expansion formula for the expectation of a function of a sample covariance matrix is derived; it is given up to the second-order term with respect to the inverse of the sample size. Two examples are given: one of calculating the asymptotic variances and covariances of the stepdown multiple correlation coefficients, and the other of obtaining the asymptotic expansion formula for the moments of sample generalized variance.     

Kronecker积AB的广义逆的表示及其应用

本文给出矩阵A和B的Kronecker积的加权Moore－Penrose逆、Drazin逆和群逆的表示，并应用这些结果给出投影算子AAMN，AMNA，AdA和AgA的行列式表示，已知的关于Moore－Penrose逆和正则逆的结果，均为本文的特例．     

The crystallization of a paranoid symptom: Three theories

The dynamics of paranoia are complex. The cognitive and behavioral patterns of paranoia are well documented in the clinical literature. However, writings on the etiology of paranoia are sparse. Sigmund Freud, Melanie Klein, and William W. Meissner are the three most comprehensive and recognized theorists on the etiology and psychodynamic functions of paranoia. Their theories are delineated and applied to a clinical vignette of a woman with a recently developed paranoid symptom.     

一类线性偏微分算子的亚椭圆性

利用拟微分算子研究了一类线性偏微分算子的亚椭圆性,得到了 Sobolev 空间范数的估计,从而得出了该类算子具有亚椭圆性的充分条件。     

附加噪声长记忆过程的半参数估计方法研究

附加噪声长记忆过程的参数估计在实证研究中一直受到回避.本文通过聚合算子对样本数据进行降噪处理,研究了局部Whittle(LW)估计和对数周期图(LP)回归两种半参数估计方法.结果表明LW估计方法相比LP回归,解决了半参数方法的参数选取问题,且能够完全忽略噪声数据的影响而得到一致的估计.将LW估计应用于中国股市,发现重大突发事件发生时的长记忆性表现得最为强烈,且事件后比事件前要强烈.     

Quasi-universal bandwidth selection for kernel density estimators

Let f?_n, h denote the kernel density estimate based on a sample of size n drawn from an unknown density f. Using techniques from L₂ projection density estimators, the author shows how to construct a data-driven estimator f?_n, h which satisfies This paper is inspired by work of Stone (1984), Devroye and Lugosi (1996) and Birge and Massart (1997).     

论2014年《蒙特利尔议定书》对1963年《东京公约》的修订

鉴于对航空器安全及机上人员财产安全的关切和对遏止机上非循规与扰乱行为的关注,经数年努力,修订1963年《东京公约》(即《关于在航空器上犯罪和犯有某些其他行为的公约》)的《蒙特利尔议定书》于2014年4月在国际民航组织主持召开的国际航空法外交会议上审议通过。该议定书在适用范围规则、刑事管辖权规则与飞行安保员规则等三方面对《东京公约》作出重要变更,其努力值得肯定。然而,对议定书与《东京公约》的对比分析和对议定书约文本身的详细考察均显示,议定书对《东京公约》的几项主要修订尚欠成熟,且存在不容忽视的问题与缺陷,势必影响其目的的实现。《蒙特利尔议定书》对《东京公约》的修订并未取得令人满意的效果,其生效前景也不容乐观。     

A study of uniformity pattern for extended designs

The objective of this paper is to investigate the issue of projection discrepancy for extended U-type or nearly U-type extended designs along the line of Fang and Qin (2005 Fang, K. T., and H. Qin. 2005. Uniformity pattern and related criteria for two-level factorials. Science China Series A 48:1–11.[Crossref] , [Google Scholar]) based on the centered L₂-discrepancy proposed in Hickernell (1998 Hickernell, F. J. 1998. A generalized discrepancy and quadrature error bound. Mathematics of Computation 67:299–322.[Crossref], [Web of Science ®] , [Google Scholar]). Extended designs are obtained through augmenting optimally few runs (or points) to an optimal U-type design. Lower bounds to projection discrepancy with reference to the centered L₂-discrepancy of extended designs have been obtained. Some illustrative examples are also provided.